I just loaded the datamodel and entered a public bookmark - go to
https://openacs.org/bookmarks, click on "view public bookmarks", and let me know if you see it.
Feel free to add your own public bookmarks.
This does seem like a cheap and easy kludge to get around the fact that we don't have sufficient navigation or a site map.
I won't worry about folks abusing the availability of this until it happens...